Inequality signs and number lines

An inequality describes a set of possible values. The signs \(<\) and \(>\) exclude equality; \(\le\) and \(\ge\) include it. On a number line an open circle excludes an endpoint and a filled circle includes it.

Example

The interval \(-2\le x<3\) contains every real number from \(-2\) up to, but not including, \(3\).

If \(x\) is an integer, the permitted values are \(-2,-1,0,1,2\). Without an integer restriction, fractions and decimals between the endpoints also belong.